Propeller



S. PIES! K Sept. 9, 1930.

PROPELLER Filed Nov. 9, 1929 Sig/d7? H26 17? @zaz (NVENTOR ATTORNEYPatented Sept. 9, 1930 UNHTED STATES PATENT. OFFICE STEFAN PIESIK, orMOUNT uNIoN, PENNSYLVANIA PnoPE Lnn Application filed November 9, 1929;Serial No. 406,034. 1

My present invention has reference to an improved construction inpropellers for use on either air or water crafts, and my primary 7object is the provision of a propeller which, while simply constructed,shall be light, strong and endurable and which shall embody a maximumamount of pulling force without straining the engine.

A further object is to produce a propeller.

It is a still further object to construct a propeller which ispreferably of metal and which has parallel blades extending in oppositedirections from the hub thereof, each of said blades being roundedoutwardly and from thence inwardly from. the concaved central portionsof the propeller, each blade, from its said outer end being divided intoa plurality of blade sections or fiukes, which are arranged angularlywith respect to each other, diamond-shaped in cross section, their inneredges disposed approximately centrally with respect to the outer edgesof the respective flukes, and whereby each fluke will exert its fullforce for the entire Width there- 'of against the air or water withwhichit con-- the different blades as they appear in Figure 2 of thedrawings. 7 My improved propeller is preferably constructed of metalwhich is light but strong and wherein an additional strength is affordedthe flukes or blades thereof by constructing the same substantiallydiamondshaped in cross section.

The improvement, from the hub portion 1 thereof, is formed withoppositely extending blades 2-.2, respectively. The blades, at theirjuncture with the hub 1 have their outer edges concaved or roundedinwardly to the central ring members 3 that surround the hub.

From thence the edges of the blades 2 are rounded or curved outwardlywith respect to 1 each other and from thence the said blades are curvedinwardly or toward each other.

Fromtheir. outer edges the blades 2 are cast or shaped to provide thesame with any desired. number of flukes. The diametrically opposed outerflukes are indicated for distinction by the numeral 4: and while all theflulres are of the same width the longitudinal length of the outerflukes 4 exceed that of the inner fiukes 5, while the space between theinner flukes and the next outer flukes 6 is less than the space ordivision between the flukes 4L and5. As disclosed by the drawings eachof the flukes 4, 5 and 6 is diamond-shaped in cross section, that is,the same from the widened center thereof merge into sharpened edges.This is one of the important features of the invention as by suchconstruction the flukes will cut through the wind or water with greaterefficiency than were the flukes otherwise shaped. The fiukes, from theirconnection withthe hub 1 are gradually spread away from each other andare oppositely curved as disclosed byFigure 2 of the drawings. The spacebetween the flukes, however, is such that one edge of the fluke 5overlies the adjacent edge of the fluke 4 and likewise underlies theinner or adjacent edge of the fluke 6.

The fluid or air stream lines that are forced between the severalflukes, during the r0ta tion of the propeller are attacked gradually andin a successive manner by all of the flukes and such contact will avoidthe eddies of dead water or dead air produced by the turning of anorinary propeller. In addition to this each fluke will exert its fullforce of contact upon the fluid stream, with the result that the vesselto which the propeller is attached will be caused to move in a forwarddirection in an easier, steadier and quicker manner than can beaccomplished by the ordinary propeller constructions.

Having described the invention, I claim A propeller for the purpose setforth, comprising a hub, a pair of oppositely extending blades fixed onthe hub, having their outer edges concaved at their connection with thehub, from thence rounded outwardly from each other and inwardly ortoward each other to their ends, said blades, from the outer ends beingdivided into central and end flakes, the division wall of two of thediametrically opposite end fiukes and the centralflukes being greaterthan the division wall between the second diametrically opposite endflakes and the inner flukes, and the space between the fiukes beinggradually increased from the inner to their outer ends, said fiukesbeing diainond-sl'laped in cross section and being gradually spaced awayfrom each other from their inner to their outer ends and disposedangularly and at opposite curvatures with respect to each other and theedges of the inner fiukes being disposed adjacent to but spaced from theinner edges of the outer flukes.

In testimony whereof I afiiX my signature.

STEFAN PIESIK.

